I suggest this topic is worthy of discussion. Not the Physics string theory, but belt drive replacements, with “string”. I will open the discussion by saying I have been using a test string belt for several months on my Prime. I never found out exactly what it is made of, but it has no noticeable stretch and my guess is it is silk or some other extremely fine fiber weave. It was probably made 25 years ago, and was sold by Top Flite as model airplane hinge thread. Whatever it is it works. A tinkerer from way back I am pleased with the results. I am posting two photos of two belts that show the relative size of each and the simple square knot I used on both secured with a tiny amount of CA. The thread is best trimmed with a small, sharp pair of sizzers, after the CA is applied. The knot should be pulled as tight as possible before adding the CA. (the way I did it). I leave it to you to guess which I like best and why. The string is not the same weave and I guess are different material. Neither has any apparent stretch. And they are similar in diameter and lengths are as close to the same as I could make them. I will post my PICK of the two tomorrow. One caveat to my tests. I do not have a speed controller. But, I have made numerous listening tests for comparison, and to me it’s still music, and the more real the better.JTA

The airplane hinge thread is more than likely Dacron which is used in sail and rip stop fabrics. It is known for its high tear strength and will not stretch.

If you are still in the thread experimental stage, you can try dental flow. Stay away from the multi filament floss and look for a teflon based mono filament floss. The nice thing about mono filament is that it does not change thickness based on the stress you put on the thread.

Over the years, I have played with various thread materials on my La Platine Verdier table and I always return to the Veridier recommended linen thread by the French manufacture Fil au Chinois.

BRFThe green one is definitely Dacron. It’s my favorite and is a woven thread made by RIO products. Its basically round and is coated with something (?). It’s fishing Fly Line Backing. Way cheaper that silk thread. 20 lb test. All the mono filament dental floss I could find says it’s a folded flat robbon, I don’t think that would be any better. What amazed me was that the green thread improvement was really obvious, and really helped vocals. I’m on to my next project for now, a pretty piece of granite that will go under my isolation block (for starters).The green belt stays, but I also want to try two of them at the same time. The threads of the Dacron are extremely fine, barely noticeable in my photo.Cheers,JTA

Update on my new TT base. I think it’s marble countertop, 1.125 inches thick. Size is 20 X 15 inches. It’s pretty hefty, I’m guessing about 35 pounds. (No bathroom scale) [Can you tell I’m impressed?] It sits on two thicknesses of square vibration pads, about 2 inches thick. Then comes a larger poplar (woodworkers) bench top with downward facing cones resting on square steel plate,that rest on the stone (steel plate roughly three inches square). Then comes my stock Prime. The setup is more complicated than described with some previous tweaks, but seems to be what my system needed (on the front end). I would encourage anyone to try a similar setup. I’m hearing new tonal accuracy and tighter base, with greater clarity and instrument resonance I had not heard before. And this is without some other tweaks I want to try. As I told someone today, this is the dream system I wanted in the 80’s! My lowly Sony receiver has never sounded so good. My phono gain is a bit noisy so I can only imagine how much better the setup can sound. If you already have a solid TT base this dual layer approach might be less than stellar for you, but then again it could be a very cheap upgrade.JTABTW, adding the stone base required the use of lifting straps, and they make changing the test setup relatively easy and quick to do.

I finally got around to making a second string belt for my Prime. Both are made of the green Rio products, Fly Line Backing mentioned previously. It may sound like a bad idea but I am using the stock motor pulley with both belts. Music has more soundstage and focus and is more relaxed (natural) with two belts. I am kind of amazed this works as well as it does. There was no noticible wear on the first green belt and there is no apparent break in period. Patients is required to get both belts close to the same circumfrence. The string is forgiving and a square knot can be loosened and adjusted if needed. You need to pull both the string and the loose ends at the same time to tighten the knot, so it will not slip, which will change the belt diameter. When the diameter is acceptable lock the knot with some CA and let it dry. Then trim the loose ends. I used a dental pick to help guide the belt installation. This can be a bit tricky as they do not stretch. My dog has the best ears in my house. After I installed the second belt his ears focused like never before, then he relaxed to enjoy the music. The larger of the two belts is on the lowest groove of the motor pulley. Would three belts be better than two? I don’t know, maybe. Anyone using two string belts have an opinion? With all this success with the string belts, I can’t imagine going back to a rubber belt. My guess is that the motor clogging effect has been reduced and that is what is improving the sound.

Mr_Putty wrote:Update on my new TT base. I think it’s marble countertop, 1.125 inches thick. Size is 20 X 15 inches. It’s pretty hefty, I’m guessing about 35 pounds. (No bathroom scale) [Can you tell I’m impressed?] It sits on two thicknesses of square vibration pads, about 2 inches thick. Then comes a larger poplar (woodworkers) bench top with downward facing cones resting on square steel plate,that rest on the stone (steel plate roughly three inches square). Then comes my stock Prime. The setup is more complicated than described with some previous tweaks, but seems to be what my system needed (on the front end). I would encourage anyone to try a similar setup. I’m hearing new tonal accuracy and tighter base, with greater clarity and instrument resonance I had not heard before. And this is without some other tweaks I want to try. As I told someone today, this is the dream system I wanted in the 80’s! My lowly Sony receiver has never sounded so good. My phono gain is a bit noisy so I can only imagine how much better the setup can sound. If you already have a solid TT base this dual layer approach might be less than stellar for you, but then again it could be a very cheap upgrade.JTABTW, adding the stone base required the use of lifting straps, and they make changing the test setup relatively easy and quick to do.

I have found a similar solution. In my case the TT sits on a wood cabinet which I knew was not ideal because I could actually feel vibrations induced by my speakers on the 1 1/4" thick oak top. I then added a 3cm thick granite base (about 75-100 lbs) to overlay the oak and have experimented with various isolation pads between the granite and oak. The best solution I found that has provided nearly total isolation from the cabinet are 4 racquetballs placed under each corner of the granite. A bit unsettling at first because the TT seemingly floats on the squished balls (no danger of them rolling BTW) but this is probably the single best tweak I have made thus far and would echo improvement comments above. The granite was free, left over from a remodel project and the racquetballs cost about $12. Simply an amazing transformation

In terms of silk thread, I found #6 silk "bead thread" at a fabric store for all of $3.50...not expensive. #6 also relatively thick compared to others I tried and thus was able to find a position on the drive pulley that gives me less than 0.8% error in speed. I will say that trying to use more than one thread or belt would seem to induce some conflict in the system and be counterproductive...at least with my pulley, each groove is cut at a slightly different diameter and is how I fine tune the platter speed.

Question for all string belt users, if I might:Have you ever tried putting rosin on your belt? Or something similar? And if so, what was the result? Also, it’s been a while since some of you said you were going to compare different thicknesses. Do you have an opinion you can elaborate on? Long story short,I returned to two rubber belts months ago and added more motor stability with one cone under the outside bottom edge. My Prime feet and motor pads all rest on pieces of 1/4 inch plywood. The Prime feet also have one steel plate on top of the plywood. Small indents capture the bearings on the feet. Then I added the second pivot.

I’m thinking of going back to my Dacron belt for comparison, but still don’t have a speed controller, so that may wait till later. JTA

Some have posted the virtues of adding a tacky substance to the string but since I moved from thin string to #6 silk bead thread I have found no need to augment the friction coefficient. The added bonus of the #6 is that the larger diameter more closely matches that of the rubber belt so I have found a groove in the drive pulley that allows me to closely match 33.333 rpm as measured by Analog Magik...I should also note that AM results for W&F are very low and consistent which tells me that slippage is not a problem.

Yes, it does take a couple of seconds longer to get the platter up to speed (22 lb TNT Mk V platter) but is not a hindrance.